L.M.Gelman, S.V.Gorpinich, V.T.Shirkov Adaptation in vibroacoustical free oscillation method |
Acoustic bulletin, Vol. 3 ¹ 3, (2000) |
| For the first time adaptation in free oscillation method is considered for diagnostics of fatigue cracks depending on measurable interfering parameter: the natural frequency of testing object. Adaptation consists in variation of parameters and structure of method depending on estimates of natural frequency of free oscillations of testing objects and is based on use of adaptive likelihood ratio. The expediency of adaptation is investigated for features on base of higher harmonics of free oscillations, feature on base of phase characteristics of higher harmonics of free oscillations, decrement of damping of free oscillations. It is shown that for features on base of higher harmonics of free oscillations and for feature on base of phase characteristics of higher harmonics of free oscillations an adaptation depending on natural frequency is inexpedient, as well as for decrement of damping in case of frequency-dependent external friction in system. It is shown that in cases of frequency-independent friction and frequency-dependent internal friction in system an adaptation of decrement of damping of free oscillations depending on natural frequency of free oscillations is expedient and it essentially raises total probability of correct diagnostics. |
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KEY WORDS: vibration diagnostics, fatigue crack, the method of free oscillations, adaptation |
| TEXT LANGUAGE: Russian |